In 1863, San Francisco's Board of Supervisors passed a law that criminalized appearing in public in "a dress not belonging to his or her sex." Adopted as part of a broader anti-indecency campaign, the cross-dressing law became a flexible tool for policing multiple gender transgressions, facilitating over one hundred arrests before the century's end. Over forty U.S. cities passed similar laws during this time, yet little is known about their emergence,...